Middlesbrough manager Aitor Karanka has acknowledged that he faces a "difficult" decision in naming a regular starting lineup.

The Smoggies have parted with £15.6m since missing out in last season's playoff final, making them the division's second-highest spenders behind Derby County.

Karanka's side have made a mixed start to the season, finding themselves on eight points from their opening five games, but the Spaniard is full of praise for his current group of players.

"It's going to be very difficult for all of them to keep their position," he told the club's official website. "We have two players in every position and its difficult for me because I have to choose the best players.

"We have a very good team and one of the best squads in the league. They are good people and we have an amazing atmosphere on the pitch."

Boro return to action this weekend when they play host to MK Dons at the Riverside.